Perspiration

Reduces body temperature.

1400 years ago people knew that sweat helped
the body to cool down, however nobody knew that
dogs don't sweat.

Perspiration, also known as
sweating, is the production of fluids
secreted by the sweat glands in the skin of
mammals.Two types of sweat glands can be found in humans: eccrine glands and apocrine glands. The eccrine sweat glands are distributed over much of the body.
In humans, sweating is primarily a means of thermoregulation, which is achieved by the water-rich secretion of the eccrine glands. Maximum sweat rates of an adult can be up to 2-4 liters per hour or 10-14 liters per day (10-15 g/min.m2), but is less in children prior to puberty. Evaporation of sweat from the skin surface has a cooling effect due to evaporative cooling. Hence, in hot weather, or when the individual's muscles heat up due to exertion, more sweat is produced.
Animals with few sweat glands, such as dogs, accomplish similar temperature regulation results by panting, which evaporates water from the moist lining of the oral cavity and pharynx.Although sweating is found in a wide variety of mammals, relatively few (exceptions include humans and horses) produce large amounts of sweat in order to cool down.
Wikipedia, Perspiration, 2019

Thermal imaging shows that dogs use
evaporation from their tongues to lose the heat.
This was known recently, however this was
portrayed in the Quran 1400 years before it was
discovered. The Quran says that those Quranic
verses are like your skin, if you peal off those
verses then you will have to cool off by panting
like a dog.

[Quran 7:175-176] And relate to them the story of him to whom
We delivered Our verses, but he
pealed himself from them, so Satan went after him, and he became one of the perverts. Had We willed, We could have elevated him through them; but he clung to the ground, and followed his desires. His metaphor is that of a
dog: if you burden it, it
pants; and if you leave it alone, it
pants. Such is the metaphor of the people who deny Our signs. So tell the tale, so that they may ponder.

In this verse the Quranic verses are like your skin, if you
peal off those verses then you will have to cool off by panting
like a dog. Today we know why,
because dogs don't perspire from their skin but
instead they have to pant.

How could an illiterate man who lived
1400 years ago have known that dogs don't sweat?

To Christians

[Quran 42.14-15]
They only disbanded after they received knowledge (of their Bible) fallaciously among them. And if it were not a word from your Lord [Allah] that postponed it to a later date, it would have been all settled among them then. And those who inherited the Book (the Bible) from them are in great suspicion of it. Therefore call them (to the Quran) and straighten your ways as you are ordered and don't follow their passions and say: "I believe in what Allah revealed of the Book (The Quran) and I was ordered to be just among you (both Christians and Jews); Allah is our Lord and your Lord, we have our actions and you have your actions, no argument between us and you, Allah brings us together and to Him we are (all) destined."

To Muslims

[Quran 6.108]
Do not curse those who call (to worship) other than Allah, so that they don't curse Allah out of spite and ignorance. This is how We [Allah] appealed to each people its own actions; then they will be brought back to their Lord [Allah] who will inform them of what they have been doing.